Contents

In pre-revolutionaryCuba, James Wormold (Alec Guinness), a vacuum cleaner salesman, is recruited by Hawthorne (Noël Coward) of the British Secret Intelligence Service to be their Havana operative. Instead of recruiting his own agents, Wormold invents agents from men he knows only by sight and sketches "plans" for a rocket-launching pad based on vacuum parts to increase his value to the service and to procure more money for himself and his expensive daughter Milly (Jo Morrow).

Because his importance grows, he is sent a secretary, Beatrice (Maureen O'Hara), and a radioman from London to be under his command. With their arrival, it becomes much harder for Wormold to maintain his facade. However, all of his invented information begins to come true: his cables home are intercepted and believed to be true by enemy agents who then act against his "cell". One of his "agents" is killed, and he is targeted for assassination. He admits what he has done to his secretary, and he is recalled to London. At the film's conclusion, rather than telling the truth to the prime minister and other military intelligence services, Wormold's commanders (led by Ralph Richardson) agree to fabricate a story claiming his imagined machines had been dismantled. They bestow honors on Wormold and offer him a position teaching espionage classes in London.

The film was shot on location in Havana, just two months after the overthrow of the Fulgencio Batista regime, and on 13 May 1959, Fidel Castro visited the film crew when they shot scenes at Havana's Cathedral Square.[5]